Abstract: Apparatus is provided, in or for a screen separator for sieving materials, for clamping one or more sieve screen frames 78 within the confines of a chassis 40 of the separator to prevent egress of material from the separator. The apparatus comprises a sheath 50 extending around and embracing the chassis 40 and one or more expandable elements 66 for urging the sheath 50 against the chassis 40 and the screen frame(s) 78 to impart uniform clamping pressure to the clamped elements. The sheath 50 is designed to provide ease of mounting and release.

Abstract: Apparatus is provided, in or for a screen separator for sieving materials, for clamping one or more sieve screen frames within the confines of a chassis of the separator to prevent egress of material from the separator. The apparatus comprises a sheath extending around and embracing the chassis and one or more expandable elements for urging the sheath against the chassis and the screen frame(s) to impart uniform clamping pressure to the clamped elements. The sheath is designed to provide ease of mounting and release.

Abstract: An industrial sieving or screening machine has a resonator rod on the separator screen. The rod extends between two spaced ends and has a transducer located at one end to excite the rod over its length to assist with deblinding the screen. The rod may be spiral in shape or shaped with other smoothly blended complex curves such as an S-shape. A spiral rod resonator fixed to the top of the sieve screen may be used as a guide for material to be screened.

Abstract: An industrial sieving or screening machine has a resonator rod on the separator screen. The rod extends between two spaced ends and has a transducer located at one end to excite the rod over its length to assist with deblinding the screen. The rod may be spiral in shape or shaped with other smoothly blended complex curves such as an S-shape. A spiral rod resonator fixed to the top of the sieve screen may be used as a guide for material to be screened.

Abstract: An industrial sieving or screening machine has a resonator rod on the separator screen. The rod extends between two spaced ends and has a transducer located at one end to excite the rod over its length to assist with deblinding the screen. The rod may be spiral in shape or shaped with other smoothly blended complex curves such as an S-shape. A spiral rod resonator fixed to the top of the sieve screen may be used as a guide for material to be screened.

Abstract: A sieve (10) has abase (3), a sieve screen frame (4) and a sieve screen (12) mounted in the frame so as to be substantially horizontal. A first vibrator (1) vibrates the frame relative to the base in a generally horizontal direction at a first frequency less than 400 Hz. A second vibrator (2) has a vibration transmission member (6) attached directly to the sieve screen and an excitation source which activates the vibration transmission member to vibrate the sieve screen (12) relative to the frame (14) in substantially vertical direction at a second frequency less than 400 Hz. The resulting activity of the screen reduces blinding in use.

Abstract: An ultrasonic sieving apparatus (10) is described which comprises a de-coupler (18) for enabling a combination of a transducer (T) and a first resonator (16) to be supported with respect to a sieve which includes a separation medium (14) provided in a frame (12) such that vibrations generated by the transducer (T) are transmitted to the separation medium (14) via the first resonator (16). The first resonator (16) is of substantially circular cross-section and has first dimensions. The ultrasonic de-coupler (18) which is also of generally circular cross-section and of second dimensions, is connected to and is concentric with the first resonator (16). In use the de-coupler (18) is attached to a bracket (20) adapted to mount the de-coupler (18) onto the frame (12).

Abstract: Sieving apparatus has a piezoelectric transducer directly bonded to a grating (100), the transducer comprising a number of piezoelectric elements (1) sandwiched between first and second bodies (2,3 ). The first body (2) is in two parts (2A, 2B) which are releasably secured together (6, 7), one part (2B) being directly bonded (5) to the grating (100). The arrangement allows use of a transducer with different gratings with different parts (2B) of a first body (2) bonded thereto in order to achieve a required operational mode.

Abstract: Sieving apparatus has a piezo-electric transducer (1) directly bonded to a grating (100), the supply to the transducer (1) being controlled by sensing resonance of the grating (100) and any deviation therefrom and controlling the supply to maintain resonance.

Abstract: A liquid strainer has a screen arranged to be vibrated by out-of-balance weights. A removable container holds a body of liquid to be strained above the screen and liquid is supplied to the container via a valve and a flexible connection. Liquid passing through the screen is collected in a tank beneath the strainer. Level detectors in both the removable container and the collecting tank control the valve to turn off liquid supply when either level exceeds a predetermined height. The entire apparatus is completely enclosed.